title: Shell layers of the black-lip pearl oyster Pinctada margaritifera: matching microstructure and composition.
abstract: The nacre-prism transition of the mollusc shell Pinctada margaritifera was studied using scanning electron microscopy, electron probe micro-analysis (EPMA) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Mineralogical change is correlated with a change in organic matrix. Previous analyses had shown that sugars were involved in the transition layer (fibrous aragonite). The new Energy Dispersive Spectrometry (EDS) and TOF-SIMS maps show that the modifications at the layer boundary are complex, and that proteins and lipids are also involved. Detailed TOF-SIMS maps show that the thick organic envelopes surrounding the prisms, and between the prisms and the fibrous aragonitic layer, are not composed by regular layers, but are a patchwork of various molecules. The amino acid compositions of the nacreous and prismatic layer are compared thanks to the TOF-SIMS localized analyses.
authors.affiliation: UMR IDES, Université Paris Sud, Orsay, France.
authors.forename: Bastien
authors.initials: B
authors.lastname: Farre
authors.forename: Alain
authors.initials: A
authors.lastname: Brunelle
authors.forename: Olivier
authors.initials: O
authors.lastname: Laprévote
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Cuif
authors.forename: C Terry
authors.initials: CT
authors.lastname: Williams
authors.forename: Yannnicke
authors.initials: Y
authors.lastname: Dauphin
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D002119:Calcium Carbonate / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D049911:Pinctada; D018629:Spectrometry, Mass, Secondary Ion
chemical_list: D000596:Amino Acids; D002119:Calcium Carbonate